libnvdimm, pfn: enable pfn sysfs interface unit testing

The unit test infrastructure uses CMA and real memory to emulate nvdimm
resources.  The call to devm_memremap_pages() can simply be mocked in
the same manner as memremap and we mock phys_to_pfn_t() to clear PFN_MAP
since these resources are not registered with in the pgmap_radix.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

tools/testing/nvdimm/Kbuild

@@ -9,6 +9,8 @@ ldflags-y += --wrap=memunmap
 ldflags-y += --wrap=__devm_request_region
 ldflags-y += --wrap=__request_region
 ldflags-y += --wrap=__release_region
+ldflags-y += --wrap=devm_memremap_pages
+ldflags-y += --wrap=phys_to_pfn_t
 
 DRIVERS := ../../../drivers
 NVDIMM_SRC := $(DRIVERS)/nvdimm

tools/testing/nvdimm/test/iomap.c

@@ -94,6 +94,54 @@ void *__wrap_devm_memremap(struct device *dev, resource_size_t offset,
 }
 EXPORT_SYMBOL(__wrap_devm_memremap);
 
+#ifdef __HAVE_ARCH_PTE_DEVMAP
+#include <linux/memremap.h>
+#include <linux/pfn_t.h>
+
+void *__wrap_devm_memremap_pages(struct device *dev, struct resource *res,
+		struct percpu_ref *ref, struct vmem_altmap *altmap)
+{
+	resource_size_t offset = res->start;
+	struct nfit_test_resource *nfit_res;
+
+	rcu_read_lock();
+	nfit_res = get_nfit_res(offset);
+	rcu_read_unlock();
+	if (nfit_res)
+		return nfit_res->buf + offset - nfit_res->res->start;
+	return devm_memremap_pages(dev, res, ref, altmap);
+}
+EXPORT_SYMBOL(__wrap_devm_memremap_pages);
+
+pfn_t __wrap_phys_to_pfn_t(dma_addr_t addr, unsigned long flags)
+{
+	struct nfit_test_resource *nfit_res;
+
+	rcu_read_lock();
+	nfit_res = get_nfit_res(addr);
+	rcu_read_unlock();
+	if (nfit_res)
+		flags &= ~PFN_MAP;
+        return phys_to_pfn_t(addr, flags);
+}
+EXPORT_SYMBOL(__wrap_phys_to_pfn_t);
+#else
+/* to be removed post 4.5-rc1 */
+void *__wrap_devm_memremap_pages(struct device *dev, struct resource *res)
+{
+	resource_size_t offset = res->start;
+	struct nfit_test_resource *nfit_res;
+
+	rcu_read_lock();
+	nfit_res = get_nfit_res(offset);
+	rcu_read_unlock();
+	if (nfit_res)
+		return nfit_res->buf + offset - nfit_res->res->start;
+	return devm_memremap_pages(dev, res);
+}
+EXPORT_SYMBOL(__wrap_devm_memremap_pages);
+#endif
+
 void *__wrap_memremap(resource_size_t offset, size_t size,
 		unsigned long flags)
 {